1. Field of the Invention
This invention relates to the oxidation of metal sulfides and is particularly concerned with enhancing the oxidation reaction by performing it in the presence of activated carbon.
2. Prior Art
In present commercial methods for treating sulfide ores and concentrates the general practice involves smelting or roasting the sulfides through a complex series of roasting and smelting operations which drive off the sulfur as sulfur dioxide. The metal values are effectively recovered by these operations, however, large volumes of sulfur dioxide are produced which are not always conveniently recovered, resulting in serious air pollution problems. In an effort to overcome this sulfur dioxide problem, hydrometallurgical processes are being proposed which are designed to convert the sulfide to elemental sulfur and recover the corresponding metal.
The primary hydrometallurgical processes for these sulfides include electrolytic dissolution and chemical leaching. U.S. Pat. Nos. 3,673,061; 3,736,238 and 3,766,026 describe effective processes for electrolytic dissolution of sulfide concentrates, while chemical leaching processes are disclosed in U.S. Pat. No. 3,767,543 and in the U.S. Bureau of Mines, Report of Investigations 7474.
These hydrometallurgical processes are illustrative of approaches being made to permit economic recovery of metals from their sulfides without creating air pollution. In furthering these developments the herein disclosed invention enhances the operability and efficiency of these processes by increasing the reaction rates and improving the yields.